§ Orodnaur (TI:28,39)
The form Orodruin (UT:459) appears already here (TI:493), but once -naur was pencilled above -ruin. Orodruin ’Mountain of Blazing Fire’ contains orod ’mountain’ (ÓROT-) and, according to The Silmarillion index, S. ruin ’red flame’ (Q. runya, compare RUN- ’red, glowing’ (PM:366) and √RUYU ’blaze (red)’ in PE17:183; but earlier it may have been either lenited gruin ’ruddy’ (ROY2-) or #ruin as in Ruinnel (see 2.7). The second element of the earlier form is clearly N. naur ’fire’ (NAR1-).